压电陶瓷作动器非对称迟滞建模与内模控制

压电陶瓷作动器被广泛应用于精密定位和控制中,但其本身存在的非对称迟滞非线性特性,严重影响了系统的定位和控制精度。针对这一问题,提出了一种基于广义Bouc-Wen模型的非对称迟滞建模方法,并利用差分进化算法辨识模型参数;基于所建的广义Bouc-Wen模型构建了其具有解析形式的迟滞逆模型,并设计了内模控制方案实现对压电陶瓷作动器的精密跟踪控制;最后在压电陶瓷作动器实验平台,对所提出的建模和控制方案进行了实验验证。对压电陶瓷作动器的建模结果表明,系统建模误差均小于0.051 0,比经典Bouc-Wen模型的建模误差降低约21%～46%;对100 Hz内幅值为20μm的期望位移信号的控制实验结果表明,所提出的控制方法具有良好的实时跟踪性能和跟踪控制精度。对100 Hz期望信号的跟踪控制均方根误差为0.491 6μm,相对误差为0.040 2μm,可以很好地满足实际工程需要。

Asymmetric hysteresis modeling and internal model control of piezoceramic actuators

Piezoceramic actuators are widely used in precision positioning and control; however, their asymmetric hysteretic characteristics severely affect the position and control accuracy of a system. To address this problem, a modeling method was proposed based on the generalized Bouc-Wen model, and the system parameters of the model were identified using the differential evolution method. Based on the generalized Bouc-Wen model, a hysteretic compensation control strategy with an analytical form was developed and an internal model control scheme to control the piezoceramic actuators was proposed. An experimental platform was developed to verify the effectiveness of the modeling and control strategy. The results of modeling a piezoceramic actuator reveal that all modeling errors are within 0.051 0. Compared with the conventional Bouc-Wen model, our proposed control model can reduce the modeling errors by approximately 21%-46%. Experimental results from the tracking of amplitudes of 20 μm and frequency signals within 100 Hz indicate that the proposed control method offers effective real-time tracking performance and control accuracy. For 100 Hz, the root mean square error and relative error between the reference and output of the piezoceramic actuators were 0.491 6 μm and 0.040 2 μm, respectively, indicating that the proposed control model can satisfy the requirements of practical applications.